It's what you get used to.

 Last night thought I'd change me strings,  so got me bag of mixed new strings out, a right mixture of make and gauge strings, picked up this set of 12s Phosphor Bronze,  thought this might make a change from the 11g Phosphor Bronze strings that I've been using for years,  so spent ages changing them to 12g strings , so tonight couldn't stand them any longer 12g strings off and back to the 11g strings , there thats a lot better.